In desktop computing, it is possible to connect a computing device to more than one display device. Traditionally, a user would have a computer with a single display device attached, but now it is possible to have more than one display device attached to the computer, which increases the usable display area for the worker.
The connection of an additional display device to a computer presents a number of problems. In general, a computer will be provided with only one video output, such as a VGA-out connection. One method by which a second display device can be added to a computer is by adding an additional graphics card to the internal components of the computer. The additional graphics card will provide an additional video output which will allow the second display device to be connected to the computer and driven by that computer. However, this solution is relatively expensive and is not suitable for many non-technical users of computers.
International Patent Application Publication WO 2005/083558 describes an alternative type of display system. A host computing device (e.g. desktop computer) is coupled to displays using a general-purpose network, such as Universal Serial Bus (USB) or Ethernet. A remote device, local to the display, acts as a network-to-video converter. The remote device has a network interface for receiving display data over the general-purpose network, storing the data in a frame buffer, and outputting the data on a video interface to the display. To minimise the amount of bandwidth used on the general-purpose network, the display data is sent in compressed form and decompressed locally at the remote device. It is also desirable that any additional hardware between the computer and the display device is kept as simple as possible. It is also desirable that the remote device is powered by the host computing device. Higher definition video content and higher resolution display devices demand higher processing at the remote device, and make it increasingly challenging to produce a high performance display control device which can be powered by the host computing device.
It is therefore an object of the invention to improve upon the prior art.